ترغب بنشر مسار تعليمي؟ اضغط هنا

Mass distributions marginalized over per-event errors

33   0   0.0 ( 0 )
 نشر من قبل Diego Martinez Santos
 تاريخ النشر 2013
  مجال البحث
والبحث باللغة English




اسأل ChatGPT حول البحث

We present generalizations of the Crystal-Ball function to describe mass peaks in which the per-event mass resolution is unknown and marginalized over. The presented probability density functions are tested using a series of toy-MC samples generated with Pythia and smeared with different amounts of multiple scattering and for different detector resolutions.

قيم البحث

اقرأ أيضاً

Estimating the kernel mean in a reproducing kernel Hilbert space is a critical component in many kernel learning algorithms. Given a finite sample, the standard estimate of the target kernel mean is the empirical average. Previous works have shown th at better estimators can be constructed by shrinkage methods. In this work, we propose to corrupt data examples with noise from known distributions and present a new kernel mean estimator, called the marginalized kernel mean estimator, which estimates kernel mean under the corrupted distribution. Theoretically, we show that the marginalized kernel mean estimator introduces implicit regularization in kernel mean estimation. Empirically, we show on a variety of datasets that the marginalized kernel mean estimator obtains much lower estimation error than the existing estimators.
Neutral meson cross-section and direct photon HBT measurements in high energy pp, pA, and AA collisions rely on either subtracting or dividing out the background underlying the $M_mathrm{inv}$ or $Q_mathrm{inv}$ distributions. In this paper we inve stigate the photon pair distributions for simulated proton-proton collisions at $sqrt{s}=13~$TeV, and show that the correlated part of the background in $M_mathrm{inv}$ gets poorly described by the conventional event-mixing method implemented in experimental analyses. We show that it fails to describe the background as it gives a qualitatively different shape especially at invariant masses around the $pi^{0}$ and $eta$ meson mass. We show that this is caused by the correlations originating from parton fragmentation, and discuss a new method that attempts to describe the correlated part of the combinatorial background by only pairing photons when the parton ancestors are close in $eta$ and $varphi$.
A study of differential event shape distributions using e+e- data at centre-of-mass energies of 35 to 183 GeV is presented. We investigated non-perturbative power corrections for the thrust, C-parameter, total and wide jet broadening observables. We observe a good description of the distributions by the combined resummed QCD calculations plus power corrections from the dispersive approach. The single non-perturbative parameter alpha_0 is measured to be alpha_0 (2 GeV) = 0.502 +- 0.013 (stat.) ^{+0.046)_{-0.032} (exp. syst.) ^{+0.074}_{-0.053} (theo. syst.) and is found to be universal for the observables studied within the given systematic uncertainties. Using revised calculations of the power corrections for the jet broadening variables, improved consistency of the individual fit results is obtained. Agreement is also found with results extracted from the mean values of event shape distributions.
Robust qubit memory is essential for quantum computing, both for near-term devices operating without error correction, and for the long-term goal of a fault-tolerant processor. We directly measure the memory error $epsilon_m$ for a $^{43}$Ca$^+$ trap ped-ion qubit in the small-error regime and find $epsilon_m<10^{-4}$ for storage times $tlesssim50,mbox{ms}$. This exceeds gate or measurement times by three orders of magnitude. Using randomized benchmarking, at $t=1,mbox{ms}$ we measure $epsilon_m=1.2(7)times10^{-6}$, around ten times smaller than that extrapolated from the $T_{2}^{ast}$ time, and limited by instability of the atomic clock reference used to benchmark the qubit.
We study the matching of the next-to-leading logarithmic approximation (NLLA) onto the fixed next-to-next-to-leading order (NNLO) calculation for event shape distributions in electron-positron annihilation. The resulting theoretical predictions combi ne all precision QCD knowledge on the distributions, and are theoretically reliable over an extended kinematical range. Compared to previously available matched NLLA+NLO and fixed order NNLO results, we observe that the effects of the combined NLLA+NNLO are small in the three-jet region, relevant for precision physics.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا